1. Field of the Invention
This invention relates to synchronizing signal generating devices and, more particularly, to synchronizing signal generating devices for generating synchronizing signals to be outputted together with video signals.
2. Description of the Related Art
The color television scanning method presently used as standard is of the NTSC system in Japan, U.S. and Canada, the PAL system in Western Europe and China, and the SECAM system in France and Eastern Europe. Of these, the PAL and SECAM systems differ from each other only in the method of carrying the color difference signals, but both are basically different from the NTSC system in the scanning standards. For this reason, in the past, to cope with these sets of standards, synchronous signal generating devices (timing signal generating devices) of sole adaptation to each were made and used.
Therefore, inasmuch as the prior known techniques differ, even for a single sort of instrument (product item), the corresponding kinds of timing generating devices to the individual sets of standards had to be designed and manufactured in such ways that one was for adaptation to the NTSC, and the other to the PAL. These became large obstacles to reduction of the development cost and the decrease in cost as a result of mass production.